#ifndef TOOL#define TOOL#include <iostream>#include <sys/stat.h>//#define BUFFER_SIZE 1024class tool {public:    tool() {}    ~tool() {}    static long getFileSize(const std::string &fileName) {            struct stat fileStat;                if(stat(fileName.c_str(), &fileStat) == -1){            std::cout << "无法访问该文件" << std::endl;            return 0;        }        return fileStat.st_size;}};#endif